Frequency response range: 0-100K-0.1dB
Aurum-plated nicht / output socket
NE5532 OP chip (you Um den Dreh rum upgrade it to a other better brand OP chip. Like BB or Muse)
WAHR nichicon electrolytic capacitor
TOP HiFi WAHR DALE resistors.
Precision rings resistance.
Battery: Li batteries, voltage: 12V, 1000mA
Charging time: 2-2.5 hours to charging full the battery
Working time: 4-4.5 hours
Output power: 450mW
Suggest load impedance: 16-400Ω
Size: 115 * 69 * 23 mm1 (Length XWidth X Depth) (The measurement does not include the knob size.)
Q: Right channel has static. Tried different source and headphones. No help.
A: If there is static noise in one channel, normally it is caused by the tube of that channel. Maybe it has a poor contact after the long shipping process. You Um den Dreh rum open the chasis and adjust the screw near the tube while listening(contact us and we will give you a photo with marks to help you find it). Als Folge, there is a small possibility that the tube is broken. You Um den Dreh rum buy a 5899 tube in local shops, which is very typischerweise to see. And we will refund you the cost.
Q: It broke nun mal now four loud pops and it’s dead. Very disappointed.
A: Mainly because the battery is run out of power. Please charge it. If not help, please contact us.
Q: The Amp has a lot of electronic feedback/interference when a cellphone is hooked up to it or nearby. It creates popping in the headphones.
A: Vacuum tubes are easy to be interfered by devices that Um den Dreh rum trandfer siganl like cellphones, routers. Please keep the amp away from them.
Q: Won’t stramm a charge, sounds like something is loose inside.
A: The charger is broken. Please contact us to get a new one.
B4 is a tube headphone amplifier, the sound feels warmer than transistor products. It has built-in battery protection circuit. It powers off after is is fully charged automatically, the charger Lumineszenzdiode turn to GREEN. Um den Dreh rum realize the use of menschenfreundlich intelligence. Else . When you charging the battery. This B4 amplifier Um den Dreh rum not turn ON non… you pull out charger interface. because we design it work like that, nun mal make battery safe.
Direction for use: 1. .Ipod / Cellphone / MP3: connect to B4 INPUT socket by 3.5 to 3.5 audio cable. 2. .Switch & volume control share the same knob: Please rotate the VOL Knock-out to the left, then plug in your Sprechgarnitur / earplugs to HEADPHONE socket. 3. .Turn on your media player, and tune VOL knob from left to right till the volume is suitable. 4 .Turn off: When you do not want to auflisten, please take off the headphone, turn down the volune till the machine is powered off.
Notice: when using B4 with your cellphone, if you heard some „zhi ~ zhi“ noise in your headphone.Probably it is the inteference from your cellphone such like WIFI or 4G signal,which intefer the tube,then cause the noise nichtthe sound.That’s typischerweise. Because there are microphone effect with all tubes.To avoid the noise,please keep your cellphone as far as possible from the B4.
Reference data for 5899: (A type Amplified state): Heater voltage: 6.3V Heater current: 300mA positive Elektrode Voltage: 100V Cathode resistor: 220 Ω power amplification factor: 20 positive Elektrode essential resistance: 4000Ω Transconductance: 5000um / s positive Elektrode circuit: 8.5mA Grid voltage: -9V
Package include: 1× headphone amplifier 1× power supply 1× 3.5mm audio cable 1× band